The Dukes of Schleswig were rulers of the historical region of Schleswig, located in present-day northern Germany and southern Denmark. The title emerged in the Middle Ages, with the dukes overseeing local governance and land management. Their authority was often contested, leading to conflicts over territorial claims. The dukes were part of the larger House of Oldenburg, which played a significant role in the politics of northern Europe. The region's complex history included various dynastic struggles, particularly between Denmark and Germany, culminating in the Second Schleswig War in 1864, which significantly altered the political landscape.